Boiler stay-bolt.



1. A. WOLMER, E. F. HANLON & 0.1. THOMSON.

BOILER STAY BOLT.

APPLlC E .l9l6. 1 ,273,563. Patented July 23, 1918.

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INVENTORS: WITNESSES: Z5 3 977 C W 7;r ATTORNEY so that deteriora UNITED STATES PATENT OFFICE.

JOHN A. WOLMER, EDWARD F. HANLON', AND GUY L. THOMSON, 0F INDIANAPOLIS,

INDIANA.

BOILER STAY-BOLT.

To all'whom it may concern:

, Be it known that we, JOHN A. WOLMER, EDWARD F. HANLON, and GUY L. THOM- soN, citizens of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented a new and useful Boiler Stay-Bolt, of which the following is a specification, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon.

' This invention relates to boilers in which steam is to be enerated and has reference more particular y to such portions of boilers as have oppositely arranged metallic sheets, as in fire-boicstructures the invention having reference more particularly to means whereby oppositely arranged sheets of the boilers'are stayed or braced.

An object of the invention is to provide an improved boiler stay-bolt that shall be adapted to be welded to and become practically integral with one of two oppositely arranged metallic sheets, more particularly the fire-box sheet, and have its maximum strength at the inside of the fire-box sheet between the two sheets, an aim being to avoid weakening the fire-box sheet by leaving bolt holes therein which hitherto has been a source of trouble and danger because of the'development of cracks in the firebox sheet at the numerous holes into which the stay-bolts have been hitherto screwed. e

Another object isjto provide an improved stay-bolt that shall, be threadless where connected to the firebox sheet and therefore not be liable to fracture adjacent to the sheet'asi's the t'endency of screw-threaded bolts hitherto used, an aim being to reduce the surface of the'stay-bolt thatis exposed 'to watei adjacent to the fire-box sheet in ordef to' lessen the accumulation of scaleforrning deposits. p y e A further object is to'provide improved In'eans'for stay'in or bracing fire-box sheets l zing leakage of water shall be prevented and the great expense entailed by the renewal of stay-bolts obviated, tothe Specification of Letters Patent.

Patented July 23, 1918.

Application filed June 19, 1916. Serial No, 104,567.

end that increased efliciency, durability and economy shall be attained in maintenance and operation.

With the above-mentioned and other objects in view, the invention consists in an improved stay-bolt having a threadless engagement portion adapted to be welded in one boiler sheet and having also another engagement portion adapted to be connected to an oppositely arranged sheet; the invention including also a novel sheet and staybolt structure. The invention consists also further in the novel parts and combinations and arrangements of parts as hereinafter particularly described and further pointed out in the. appended'claims.

Referring to the drawings,-Figure 1 is a side view of the improved stay-bolt as preferably constructed; Fig. 2 represents one end of the stay-bolt; Fig. 3 represents the opposite end of the stay-bolt- Fig. 4 is a longitudinal central section of the preferred form of stay-bolt; Fig. 5 is a fragmentary sectional elevation of boiler sheets and the improved stay-bolts connected therewith; Fig. 6 is a side view of a modified form of stay-bolt; Fig, 7 is a side view of another modified form of stay-bolt that is ada ted to be nonrigidly connected to the shel or outer sheet of a boiler; Fig/8 is an end View of the staybolt shown in the preceding Fig. 8;

Fig. 9'is a fra nentary sectional elevation herein referred a of the boiler s eets and the. modified staybo'lts shown in Fig. partially connected therewith, aiidFi 10 is a fragmentary sectional elevation o the boiler sheets to which the stay-bolt shown in the preceding Fig. 9 is completely connected.

" Like reference characters onthe various figures of Ithe drawings indicate correspondingi'eleinents or features of. construction In the eonstruetion er a fire-boxand some rtions of boilers ahouter sheet or shell 1 is cominonl coniprisedin the structure and has a sj itableriiirnber er holes e-ih which are screwithreadsf there being an o csite1y amnged new or fire' box sheet 4.

For the purpose of the present invcntion'the inner sheet 4 is provided with plainor threadless holes 5 which are tapering so as to have an inclined or concave face 6, the smaller end or orifice of each hole being at the inside of the sheet or that side which is the nearer to the shell or outer sheet.

The preferred form of stay-bolt comprises an engagement portion 7 having screw threads 8 thereon to be engaged with the sLL'GW threads 3, and a body portion 9 extending from the engagement portion, the

bml ortion being-- cylindrical and plain or evoid of screw threads. The body portion has a tapering engagement orti'on 10 thereon which has an approximate y flat end 11'. The body portion 9 preferably is *gli'tly greater in diameter than the hole d the tapering portion is suiiielently g to extendthrough the hole a suliicient diitance to permit ofits being upset Into the hole without necessitatin cutting off operations. The opposite en of the engagement portion 7 has a squared portion 12 be engaged by a wrenchwhen applying Holt, and preferably the engagement portitn 7 has a leakage channel 13 t 'erein when a tell-tale stay-bolt is desired. When the engagement portion 10 is permanently conected to the sheet 4 it forms or constitutes a substantially homogeneous portion 14: that is substantially integral with the sheet 1, as illustrated in Figf 5, the body portion 9 being substantially integral with the inside of the sheet.

In some cases when gthere is a frame or a pad on the outside ofth'e sheet 1 the staybolt must be first inserted in the fire-box sheet 4 and thence into the outer sheet 1, in which case the stay-bolt has an engageinent portion 15 provided with the screw threadsS and the body portion 16 that is cylindrical throu hout and of suitable diameter to closely it in a hole 5. The threaded portion is, screwed into the hole 3, being tightly fittedftdthe hole as usual. The body ortioii extends through the, hole 5 when first placedin position and has a squared endgpor tion ,17Qto be engaged by a wrench. hel suj p1usageofmeta is subsequently cut piij i'nthe fire-boa and after the bolt is perma nentlymconnected to thefire-box sheet 4 it forms or comprises a substantially homogeneous or integral portion 18 with the fireboxsheet, the bod portion lfil being racnc ig, integral t the inside r the, s eet. eh it is desired that staybfilts have ,a, ball-and-isocket connection with the ld ligho i g i isfi e? he ib i the Fstay" a 21-9 spre s ci a @9 ra i .ha itaala l r hg sgli asae esitP9 1 a ane 4? that a 1e11, se e rea Pit a,: errg igr d gg leg? amass ra ens era i body portid n 19' 1s suitalile dlameter to sheet closely fit into the hole 5 to permit the engagement portion 20 to be properly connected with the outer sheet. The engagement portion 21 when ernranently connected to the fire-box sheet 4, forms or comprises a substantially homogeneous portion 23 practically in' ral with the firebox sheet. This type 0 stay-bolt extends through a bushing 24 which has screw threads 25 that engage the screw threads 3, each bushing being inserted in a hole 2. The engagement portion 20 is seated in the outer end of the bushing an usually is covered by a cap 26 that is removably screwed onto the bushing.

After each stay-bolt is connected to the outer sheet or shell 1 of the boiler" structure, the end of the stay-bolt in the fire-box may be cut off if unnecessarily long. A blowflame, which maybe obtained from acetylene gas, is directed into the concave hole and about the engagement portion of the stay-bolt, and thus the inside portion of the fire-box sheet where the bolt hole closely receives the metal of the stay-bolt is first heated, after which the end portion of the stay-bolt and the adjacent portions of the sheet are brought to a welding heat. In some cases the space around the engagement portion within the concave hole is filled or partially filled with metal which is heated and fused with the metal of the bolt and the sheet; or, the metal of the bolt may be upset while heated to fill the hole while the mass is welded together. When the squared portion 12 is cut off from the engagement portion 7 the engagement portion is preferably upset so as to form a steam-tight engagement portion 7 as is customary.

It will be apparent from the foregoing that the inner or firebox sheet that is exposed to intense heat has ractically integral stay-bolts thereon, and therefore the leakage of water into the fire-box space cannot occur and there is no tendency of the sheet to crack, there being no holes in the from which cracks might develop. The life of the fire-box sheet is therefore materially lengthened as compared with the life of a perforated sheet.

Having thus described the invention, what is claimed as new is 1. A stay-bolt comprising a cylindrical body portion having a plain threadless tapered engagement portion adjacent to one end thereof, a threaded engagement portion on the opposite end of t e body portion, and a squared end portion adjacent to the threaded engagement portion.

2, In boilerstay structure, the combination with an outer boiler sheet'having screwthreadecil holeslthereinhoi an inner lioiler I andstay bolts integrally connected to the inner boiler sheet, the stay-bolts e xtend ing through the screw-threaded holes and being connected to the outer sheet by means of the screw threads in the holes.

3. In a boiler-stay structure, the combination with an outer boiler sheet having screwthreaded holes therein, of an inner or firebox sheet arranged opposite to the outer sheet and having tapered holes therein, the larger ends of the holes being the farther from the outer sheet, and stay-bolts having threadless engagement portions extending into and through the tapered holes to be jointlessly JOHN A. WOLMER. EDWARD F. HANLON. GUY L. THOMSON.

Witnesses:

E. T. SILVIUS, J. H. GARDNER.

Copies of this patent may be obtained for five cents each, by addressing the flommlssioner of Patents, Washington, D. 0. 

